Michael Copps, a longtime member of the U.S. Federal Communications Commission, will resign effective Jan. 1, or earlier, depending on Senate action, he announced Tuesday.

Copps, a Democrat, has served on the commission since May 2001. During his tenure, he advocated for net neutrality rules, for stricter limits on how many media outlets large corporations could own, and for government programs to assist deployment of broadband to rural areas.

Copps' resignation was expected. His term is ending, and in October, President Barack Obama nominated Democrat Jessica Rosenworcel and Republican Ajit Pai to replace Copps and fill an open Republican seat on the commission.

Rosenworcel, senior communications adviser to the U.S. Senate Commerce, Science and Transportation Committee, is a former legal adviser to Copps Pai, a partner at the Jenner and Block law firm in Washington, D.C., and a former deputy general counsel at the FCC.

The Senate Commerce Committee has scheduled a vote on the nominations of Pai and Rosenworcel for Thursday. Senator Chuck Grassley, an Iowa Republican, has threatened to hold up the nominations over concerns he has about the FCC's handling of LightSquared's application to create a nationwide mobile broadband network.

Copps said it has been an "honor" to serve as a commissioner for 10 years. "Ubiquitous, opportunity-creating broadband and a resource-rich media capable of informing our civic dialogue are critically important components of our future success as a people, and I intend to keep speaking about these challenges as a private citizen in the years ahead," he said in a statement.